1. Field
This application relates generally to global navigation satellite systems (GNSS), and more specifically to providing visual indicators on a live image on a GNSS device for stakeout of a point of interest.
2. Description of Related Art
Navigation receivers that utilize the signals of the global navigation satellite systems, e.g., GPS and GLONASS enable various positioning tasks with very high accuracy. For example, a GLONASS receiver receives and processes radio signals transmitted by the navigation satellites. The satellite signals are carrier harmonic signals that are modulated by pseudo-random binary codes which, on the receiver side, are used to measure the delay relative to a local reference clock. These delay measurements are used to determine the so-called pseudo-ranges between the receiver and the satellites. The pseudo-ranges are different from the true geometric ranges because the receiver's local clock is different from the satellite onboard clocks. If the number of satellites in sight is greater than or equal to four, then the measured pseudo-ranges can be processed to determine the user's single point location X=(x, y, z)T (all vectors are represented as columns; the symbol T denotes matrix/vector transpose), as well as compensate for the receiver clock offset.
Stakeout is an example of a particularly useful GNSS application. During stakeout, a specified location is located and a marker is positioned at the physical location. A GNSS device may allow stakeout to occur with a high degree of positional accuracy, e.g., down to the centimeter level. Stakeout is useful in many applications, including construction, agriculture, and scientific research.
When performing stakeout for a particular point of interest with a GNSS device, a user may use the current location provided by the GNSS device to determine the relative location of the point of interest. The user may then move in what the user believes to be the direction of the point of interest. However, it may not be simple to determine which direction to move in, especially when the point of interest is within 10 s of meters. It may be especially difficult to determine the direction of the point of interest when the GNSS device is within centimeters of the point of interest.